Industrial Grade pH Digital Controllers Wall Mounted with Matching Pin

The HI21 controllers are simple to operate, microprocessor-based pH process controllers packed with features. With HI21 quick one,
two or three point calibration at pH 4.01, 7.01 and 10.01 comes standard and you can choose from ON/OFF, proportional and PID control to save on chemicals. These instruments have a differential input, extending electrode life by eliminating ground loop current through the reference.